Make sure unaccent extension is enabled and plays nice with migration

src/DocumentDbTests/Indexes/NgramSearchTests.cs

@@ -44,8 +44,6 @@ public async Task test_ngram_search_returns_data()
         var store = DocumentStore.For(_ =>
         {
             _.Connection(Marten.Testing.Harness.ConnectionSource.ConnectionString);
-
-            // This creates
             _.Schema.For<User>().NgramIndex(x => x.UserName);
         });
 
@@ -83,7 +81,6 @@ public async Task test_ngram_search_returns_data_using_db_schema()
         var store = DocumentStore.For(_ =>
         {
             _.Connection(Marten.Testing.Harness.ConnectionSource.ConnectionString);
-
             _.DatabaseSchemaName = "ngram_test";
 
             // This creates an ngram index for efficient sub string based matching
@@ -118,11 +115,10 @@ public async Task test_ngram_search_returns_data_using_db_schema()
 
     [Fact]
     public async Task test_ngram_on_nested_prop_search_returns_data()
-    {
+{
         var store = DocumentStore.For(_ =>
         {
             _.Connection(Marten.Testing.Harness.ConnectionSource.ConnectionString);
-
             // This creates
             _.Schema.For<User>().NgramIndex(x => x.Address.Line1);
         });
@@ -164,8 +160,6 @@ public async Task test_ngram_when_using_non_ascii_characters(){
         });
 
         await using var session = store.LightweightSession();
-
-
         //The ngram uðmu should only exist in bjork, if special characters ignored it will return Umut
         var umut = new User(1, "Umut Aral");
         var bjork = new User(2, "Björk Guðmundsdóttir");

src/Marten/Schema/DocumentSchema.cs

@@ -46,7 +46,7 @@ public DocumentSchema(DocumentMapping mapping)
     public IEnumerable<Type> DependentTypes()
     {
         yield return typeof(SystemFunctions);
-
+        yield return typeof(RequiredExtensions);
         foreach (var referencedType in _mapping.ReferencedTypes()) yield return referencedType;
     }
 

src/Marten/Storage/RequiredExtensions.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using Weasel.Core;
+using Weasel.Core.Migrations;
+using Weasel.Postgresql;
+
+namespace Marten.Storage;
+
+internal class RequiredExtensions: IFeatureSchema
+{
+    private readonly StoreOptions _options;
+
+    public RequiredExtensions(StoreOptions options)
+    {
+        _options = options;
+    }
+
+    public ISchemaObject[] Objects => [new Extension("unaccent")];
+
+    public string Identifier => "requiredextensions";
+
+    public Migrator Migrator => _options.Advanced.Migrator;
+
+    public Type StorageType => typeof(RequiredExtensions);
+
+    public IEnumerable<Type> DependentTypes()
+    {
+        yield break;
+    }
+
+    public void WritePermissions(Migrator rules, TextWriter writer)
+    {
+        //Nothing
+    }
+}

src/Marten/Storage/StorageFeatures.cs

@@ -42,6 +42,7 @@ internal StorageFeatures(StoreOptions options)
         _options = options;
 
         SystemFunctions = new SystemFunctions(options);
+        RequiredExtensions = new RequiredExtensions(options);
     }
 
     /// <summary>
@@ -50,6 +51,7 @@ internal StorageFeatures(StoreOptions options)
     public List<ISchemaObject> ExtendedSchemaObjects { get; } = new();
 
     internal SystemFunctions SystemFunctions { get; }
+    internal RequiredExtensions RequiredExtensions{get;}
 
     internal IEnumerable<DocumentMapping> AllDocumentMappings =>
         _documentMappings.Value.Enumerate().Select(x => x.Value);
@@ -262,6 +264,7 @@ public IFeatureSchema FindFeature(Type featureType)
 
     internal void PostProcessConfiguration()
     {
+        Add(RequiredExtensions);
         SystemFunctions.AddSystemFunction(_options, "mt_immutable_timestamp", "text");
         SystemFunctions.AddSystemFunction(_options, "mt_immutable_timestamptz", "text");
         SystemFunctions.AddSystemFunction(_options, "mt_immutable_time", "text");
@@ -278,7 +281,7 @@ internal void PostProcessConfiguration()
         SystemFunctions.AddSystemFunction(_options, "mt_jsonb_move", "jsonb,text[],text");
         SystemFunctions.AddSystemFunction(_options, "mt_jsonb_path_to_array", "text,char(1)");
         SystemFunctions.AddSystemFunction(_options, "mt_jsonb_remove", "jsonb,text[],jsonb");
-        SystemFunctions.AddSystemFunction(_options, "mt_jsonb_patch", "jsonb,jsonb");
+        SystemFunctions.AddSystemFunction(_options, "mt_jsonb_patch", "jsonb,jsonb");        
 
         Add(SystemFunctions);
 
@@ -303,6 +306,7 @@ internal void PostProcessConfiguration()
 
     internal IEnumerable<IFeatureSchema> AllActiveFeatures(IMartenDatabase database)
     {
+        yield return RequiredExtensions;
         yield return SystemFunctions;
 
         if (_options.Events.As<EventGraph>().IsActive(_options))